GENETICS REVIEW Chapter 11

Who is the “Father of Genetics”? Gregor Mendel When 2 alleles DON’T BLEND but BOTH ALLELES ARE EXPRESSED it is called _______________ Codominance incomplete dominance Codominance

Transmission of characteristics from parents to offspring is called ___________________. _____________ is the study of how characteristics are passed on from one generation to the next. Heredity Genetics

__________________ = An allele that IS MASKED BY the presence of another allele Recessive The way an organism physically looks is called its _____________ Phenotype

Another name for heterozygous Hybrid The diagram at the right is called a _____________ Punnett square

__________________ = An allele that MASKS the presence of another allele Red and white flowers producing pink offspring is an example of _______________________ Codominance incomplete dominance Dominant Incomplete dominance

A recessive gene is represented by a _________________ letter. lower case upper case lower case What phenotypic ratio would you expect to see in offspring from a monohybrid cross of 2 heterozygous parents? 3:1 Dominant:Recessive

_______________ are different forms of a gene for a trait. ALLELES

A dominant gene is represented by a ____________ letter. (usually the first letter of the trait) capital When a heterozygous individual shows a blending of 2 alleles instead of one being dominant over the other it is called _______________________. Incomplete dominance

When both alleles in the pair are the SAME the organism is _______________ or __________ 9:3:3:1 HOMOZYGOUS PURE What phenotype ratio is a clue that there has been a dihybrid cross between 2 heterozygous parents?

R = red flowers r = white flowers Red pink An Rr organism would have ____________ flowers if this trait was COMPLETELY DOMINANT. An Rr organism would have ____________ flowers if this trait was INCOMPLETELY DOMINANT. An Rr organism would have ______________ flowers if this trait was CODOMINANT. BOTH red & white

What are Mendel’s 2 laws of heredity? Law of Segregation Law of Independent Assortment F1F1 The offspring of the P 1 generation are called the ____ generation

Copyright Pearson Prentice Hall MEIOSIS When homologous chromosomes form tetrads in meiosis I, they exchange portions of their chromatids in a process called: _________________________ Crossing-over produces new combinations of _____________ CROSSING OVER ALLELES

When both alleles in the pair are DIFFERENT the organism is _________________ or _____________ HETEROZYGOUS HYBRID monohyrid A cross that involves only 1 trait is called a ____________ cross.

T = Tall t = short The genotype of the offspring from the cross at the right is _________. Their phenotype is _________. Tt tall

Which of the following genotypes is homozygous? TT Ww Bb rr mm BB Tt TT rr mm BB pure Another name for homozygous is ________.

In the cross at the right __________ is dominant for flower color. red Tt Mm Rr Which of the following genotypes is from a heterozygous organism? Tt SS bb Mm Rr kk

meiosis The Law of Segregation and the Law of Independent Assortment are the result of the movement of chromosomes during ___________ mitosis meiosis

Crossing a red haired horse with a white haired horse produces a roan colored horse. (Both alleles for hair color show together). This kind of inheritance is called ___________________ Co-dominance

Crossing individuals from the P generation produces the ____ generation. F1F1 DNA A gene is a segment of ______. DNA PROTEIN RNA CARBOHYDRATE

L = Blue legs l = yellow legs Blue green An Rr organism would have ____________ legs if this trait was COMPLETELY DOMINANT. An Rr organism would have ____________ legs if this trait was INCOMPLETELY DOMINANT. An Rr organism would have ______________ legs if this trait was CODOMINANT. BOTH Blue & yellow

The parents in this cross are _____________ Homozygous Heterozygous Heterozygous If G is dominant for green pods and g is recessive for yellow pods, what percentage of the offspring will have green pods? _______% 75 GGGg gg G g G g

Bb B b The genotype of the offspring in the blue box is _______ bb The offspring in the blue box is homozygous heterozygous homozygous

If you cross a homozygous RED flowered four o’clock plant with a homozygous WHITE flowered plant, ALL of the offspring produced have PINK flowers. This type of inheritance in which the heterozygote (Rr) shows a blending of traits is called __________. A. Dominant/recessive inheritance B. Co-dominance C. Incomplete dominance

What are the possible phenotypes of their offspring? (% and color) Red throats (R) are dominant over white (r) throats in Goonie birds. Make a cross between a PURE RECESSIVE and a HETEROZYGOUS Goonie bird. 50% red throats 50% white throats Rr rr R r r

What are the possible phenotypes of their offspring? (% and color) Black eyes (B) are dominant over red eyes (b) in rats. Make a cross between two HETEROZYGOUS rats. 75 % black eyes 25% red eyes B b B b BB Bb Bb bb

The parents in this cross are _____________ Homozygous Heterozygous Homozygous If W is dominant for long wings and w is recessive for short wings, what percentage of these offspring will have short wings? _______% 0% only ww makes it short

Who is the “Father of Genetics”? Gregor Mendel Which of the following genotypes could be from a HETEROZYGOUS organism? TT Rr Ww bb XX Ss Rr Ww Ss

What kind of cross is this? Pure dominant X pure recessive Heterozygous X heterozygous Heterozygous X homozygous Hybrid recessive X hybrid pure Heterozygous X Homozygous Another name for heterozygous is _______________ hybrid

What is the probability the offspring will have straight tails? In Reebops curly tails (T) are dominant over straight tails (t). Make a cross between a HOMOZYGOUS DOMINANT and a HOMOZYGOUS RECESSIVE Reebop. 0% All will be Curly tailed (Tt) Tt Tt Tt T T t

What do we call the offspring of the F 1 generation? F 2 generation Which of the following genotypes could be from a HOMOZYGOUS RECESSIVE organism? TT bbRr Ww tt XX aa bb tt aa

Aa A a The genotype of the offspring in the blue box is __________________ homozygous heterozygous heterozygous How many of the offspring from this cross will show the dominant characteristic? (75%) – AA and Aa

Gg G GGGg g gg G is dominant for green pods. g is recessive for yellow pods. What is the genotype of the offspring in the shaded box? Gg What is the phenotype of the offspring in the shaded box? Green pods

Which of the following is NOT TRUE? Genotype determines phenotype Alleles are different forms of the same gene. Genotype is the way the genes make you look. Organisms with different genotypes can have the same phenotype. T T F T Tt and TT both look tall

What are the 3 different kinds of inheritance you learned about? Dominant/recessive Incomplete dominance Co-dominance Offspring of the P 1 generation are called ______ F 1

What will the offspring be like? (% and color) Purple (P)is the dominant color for monsters. Yellow is recessive (p). Make a cross between a HOMOZYGOUS purple and a yellow monster. 100% purple Pp P P p

What genotype would a PURPLE dad have to be to make a yellow monster baby with a Purple (Pp) mom monster? Pp ? ? pp Pp Dad needs to have: a little p to give one to the baby a big P to be purple himself